* Use 'context' instead of 'here'.
* Use 'portal_type' as expression cache key.
* Use is.*Type accessors.

This commit requires [32324].

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32337 20353a03-c40f-0410-a6d1-a30d3c3de9de